code: def get_mock_dataset(dataset_dir: str):
      data_folder = os.path.join(dataset_dir, "data")
      wav_folder = os.path.join(dataset_dir, "wavs", "speakers")
  
      os.makedirs(data_folder, exist_ok=True)
      os.makedirs(wav_folder, exist_ok=True)
  
      mocked_train_samples = _save_samples(dataset_dir, "train", 1)
      mocked_valid_samples = _save_samples(dataset_dir, "valid", 111)
      mocked_test_samples = _save_samples(dataset_dir, "test", 1111)
  
      return (
          mocked_train_samples,
          mocked_valid_samples,
          mocked_test_samples,
      )
  
file_path: audio/test/torchaudio_unittest/datasets/fluentcommands_test.py
imports: import csv
  import os
  import random
  import string
  from torchaudio.datasets import fluentcommands
  from torchaudio_unittest.common_utils import get_whitenoise, save_wav, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 4 for calling a global function with example usage: get_mock_dataset(dataset_dir) and returns: mocked_train_samples,  mocked_valid_samples,  mocked_test_samples